Corner square



Jan. 26, 1965 a. K. ANVDERSON CORNER SQUARE 2 Sheets-Sheet 1 Filed Oct. 31, 1962 INVENTOR BEAUMONT \(Auoaesou ATTORNEY Jan. 26, 1965 B. K. ANDERSON 3,167,101

CORNER SQUARE Filed Oct. 51, 1962 2 Sheets-Sheet 2 IMIIIIN INVENTOR BEAUMONT K .Auoezsou ATTORNEY United States Patent 3,167,101 CGRNER SQUARE Beaumont K. Anderson, 9210 S. Van Ness, Los Angeles, Calif. Filed Get. 31, 1962, Ser. No. 234,331 Claims. (Cl. 144-2) This invention relates to tools, and more particularly to power operated tools for cutting out the rounded corners in rectangular openings of frames for doors and windows.

In the manufacture of door, window, and similar frames with a rectangular opening or openings therein and with the corners of the openings rounded or curved, or on an arcsuch as that created by a router bit, it is necessary to square the corners in order that a panel with squared corners either of glass, wood or other materials may be properly positioned in and secured in the frame. Previously, these rounded corners have been chiselled out by hand, cut out by sabre saw, or cut out by using a chain mortise. Not only are these prior methods slow and inaccurate, but in most cases they leave a tear or splinter effect on one or both sides of the frame. In the final assembly of the frame, it is therefore necessary to patch and sand the splintered sides of the frame. Obviously, these prior methods of removing rounded corners from wooden frames or frames of other suitable material, are time consuming, produce an inferior product, and are quite expensive. Accordingly, it is a primary object of this invention to provide a new and improved power operated tool for removing rounded corners from wooden frames so as not to tear or splinter either side of the frame and which may be used in a rapid and highly efficient manner.

'It is another object of the invention to provide a power operated tool to be used for removing rounded corners from frames without requiring any particular skill on the part of the operator, which requires a minimum of manual effort, and results in a substantial saving of labor because corners are squared by the device much more rapidly and accurately than by previous methods and apparatus, and in final finished form or condition.

It is yet another object of the invention to provide a tool for cutting rounded corners in rectangular frames which have four separate individual cutting chisels arranged in such a manner that each chisel is used to square a diiferent corner of the frame and it is not necessary to rotate the tool during use.

It is still another object of the invention to provide a device for cutting rounded corners from a rectangular openingin a door or like frame or structure which is provided with retractable sets of guides or locating legs whereby the device may be rapidly slid along the upper surface of the frame from one corner to the next without lifting or rotating the device while moving it from one corner to the next. The locator legs also automatically properly align the chisels of the device with the inside 7 edges of the frame.

It is still yet another object of the invention to provide a power operated cutting tool having handles mounted thereon in such a manner that the tool may be easily maneuvered and lifted manually by a person, and also having control means on the handle for instantly controlling operation of the tool without the operator removing s atter Patented Jan. 26, 1965 eration of the following detailed description taken in connection with the accompanying drawings, wherein:

FIG, 1 is an enlarged fragmentary bottom view of a cut-out opening in a wooden frame showing the corner square mounted on one corner of the opening;

FIG. 2 is a schematic view showing the electrical and pneumatic system for controlling the corner square;

FIG. 3 is an enlarged vertical cross-sectional view taken substantially on the plane of line 3-3 in FIG. 1;

FIG. 4 is a plan view of the device shown in FIG. 3;

FIG. 5 is an enlarged vertical cross-sectional view taken substantially on the plane of line 55 in. FIG. 3;

FIG. 6 is a front elevation view of the invention;

FIG. 7 is a vertical cross sectional view taken substantially on the plane of line 77 in FIG. 6;

FIG. 8 is a cross-sectional view taken substantially 0n the plane of line 8-8 in FIG. 6;

FIG. 9 is a vertical cross sectional view taken substantially on the plane of line 9-9 in FIG. 8;

:FIG. 10 is a perspective view of a chisel or cutter.

FIG. -1 illustrates a portion of a conventional frame which may be a wooden door, window frame, or other such frame structure 10 of rectangular configuration having a rectangular opening 12 formed therein by a tool which has left rounded corners =14, 16, 18% and 2t) in the four corners of the opening. In order for suitable panels or the like of wood, plastic or other suitable material, or. glass panes, louvres, or the like to be installed within the opening 12, the rounded corners must be squared. For this purpose I provide a novel tool 14 for squaring corners in a door or window frame or the like structure.

The corner squaring tool 14 includes a square and generally flat base plate Shaving formed integral therewith and at the center thereof a square guide boss 7 which projects downwardly from the bottom surface thereof. Directly above the boss 7 and also formed integrally with the base plate 5 is a square extension 2%} (FIGURE 7). The extension 20 is concentric about the center of the base plate and has formed in its upper surface an annular recess 22. An open ended cylinder =24 is provided with a pair of annular flanges projecting from its ends, one of which extends into the annular recess 22, and the other of which extends into an annular recess 26 formed within a generally square cylinder head plate 28. Each of the four corners of the head plate 28 are provided with bores which slidably receive cylinder mounting bolts 30 (FIGURE 3). Each of the bolts 30 have one end provided with a bolt head in contact with the cylinder head plate and another end threaded into one corner of the square projection 20. Thus it is apparent that the bolts 30 secure the cylinder 24-, the cylinder head 23 and the base plate 5 in assembled relationship. The interior of the cylinder 24 is thus completely sealed, and'for this purpose gaskets may be employed within the recesses 26 and 2.2.

A circular piston 32. is slidably mounted within the cylinder 24, and the side surfaces of the piston are sealed in relation to the inner surfaces of the cylinder by means of a pair of, conventional piston or sealing rings 34-.

A circular piston rod slidably extends through a bore in the center of the base plate 5 and is sealed in relation thereto by means of conventional sealing rings 38 (FIGURE 7) The upper end of the piston rod 36 is provided with a reduced portion 449 which extends through a bore in the center. of the piston and is sealed in relation to the piston by means of a sealing ring 42. The end portion 40 is provided with a threaded cylindrical recess 44 while the upper end of the piston is provided with a circular recess 46. The end portion 4d extends into a central bore 45 in the piston coaxial with recess 46. A

washer 47 is located in recess 46 coaxial with bore 45 and a standard socket head cap screw 49 extends through valve are disclosed in U.S. Patent No. 2,641,229.

of the piston rod 36 is provided with a reduced end portion 58 having a cylindrical threaded recess 52 formed therein. The end portion 58 extends through a circular bore 53 in the center of a rectangular chisel support 54 formed with a circular recess 56. A standard socket head cap screw 49 extends through a washer 47 in recess 56 and is threaded into recess 52 thereby tightly securing the chisel support to rod 36.

t The chisel support 54 is preferably of the same size and shape as the guide boss or block. 7. The boss or block 7 and the support 54 are each provided with four equally spaced aligned bores 21 and 23 respectively. Each pair of aligned bores receives opposite ends of one of the circular guide rods 62. The upper end of each guide rod is provided with a pair of annular grooves 64 and 66. A portion of each groove 66 receives the inner end of a stud 68 threaded through an edge portion of the square extension 21. Thus, the studs 68securely fix the guide rods 62 to the base plate. The annular grooves 64 are each provided with an annular seal ring'to prevent leakage around the outer surface of the rod 62 from the cylinder 24. The chisel support 54 is slidably mounted on the lower ends and central portions of the guide rods 62.

The chisel support 54 is formed with four recesses 70 in the four corners thereof. Each recess contains a chisel 72 also of rectangular cross section and having outer surfaces that are preferably flush with the outer surface of the support 54. The portions of each chisel which extend above support 54 are hollowed out so as to be angle shaped and have a vertical edge 74- in alignment with a pair of side surfaces of the support 54. The upper end of the chisels 72 are each provided with a pair of knife-like edges '76 and 78 coplanar with the sides of the support 54 below the knife-like edges and extending at right angles with one another. Each chisel is provided with a pair of chamfered bores which receive screws 86 threaded onto the support 54. Each of the four corners 7 of the guide boss or block 7 is provided with a recess 82 preferably of square cross section and of a size and depth sufiicient so that an end portion of each one of the angleshaped chisels 72 extend thereinto. A generally rectangular female die 84 is secured at each corner of the boss 7 to the lower surface of the base plate by means of. a screw 86. As shown in FIG. 9 each screw or bolt 86 is provided with a head which bears against a washer 88 on the upper surface of the base plate and the shank of the screwextends through a bore in the base plate and its lower end is threaded into the die 84. Each female die 84 extends in a radial direction in relation to the piston rod 36 and has an inner end provided with a right angular recess or cut out 88 which receives a corner of the boss 7. As shown in FIG. 8, each recess 88 is larger than the recesses 82 whereby the end portions of each recess 88 completely enclose a recess 82 and bear against the side walls of the boss 7. Thus, eachpair of recesses 82and 88 define a square opening 83.

A pair of hollow knurled cylindrical handles 98 (FIG- URES 4 and 6) are secured to the upper surface of the base plate on opposite sides of cylinder .24- by means of bolts 92 which extend through bores in the bottom of the base plate and are threaded into the bottom portions of the handles. The bottom surface of each handle is canted in relation to its longitudinal axis whereby the handles slope rearwardly in parallel relationship as shown in FIGS. 3 and 4. V

A solenoid operated valve 94 is mounted on the base plate 5 directly behind cylinder 24. The details of this Valve 94 is shown schematically in FIG. 2 and includes a sliding cylindrical valve member 86 mounted within a valve cylinder 9 8. A pair of electric solenoids 11M and 1112 are mounted within opposite ends of the cylinder 98. The upper central portionof the cylinder Q8 is provided with a port connected by means of a conduit 164 to a v the leg 136.

source of compressed air. The bottom central portion of the cylinder 98 is provided with a pair of recesses 1116 and 1119, the inner edges of which are in communication with conduits 118 and 112 respectively. The opposite ends of the cylinder 98 are provided with vent ports 114 and 116, and the center of the valve member 96 is provided with an annular groove 118. As shown in FIGS.

7 2, 6 and 7, the conduit 118 is formed in the base plate 16 and connects with the bottom of cylinder 24- while the conduit 112 extends externally of the cylinder and is connected to the top thereof.

A pair of push button switches 120 and 122 operated to release position by spring means, not shown, are mounted in the upper ends of the handles 90 as shown in FIGS. 2 and 6. The switches 12!) and 122 are connected in parallel between a source of electricity and the solenoids 1'92 and 160 respectively by means of conductors 124, 126 and 128. The conductor 128 is connected to the source of electricity by means of a main on-off switch 130 which is mounted on the top of the cylinder 24.

A cushion plate 132 (FIGURE 7) composed of fiber board or some other relatively soft material is secured to the bottom surface of the base plate 5 by means of a plurality of flat headed recessed screws 134 (FIGURE 8). The cushion plate 132 is preferably of the same shape and size as the base plate 5, is preferably of the same thickness as the'dies 84, but as illustrated in FIG. 8 has its center cut out so as to snugly fit around the side edges of the guide boss 7 and dies 84.

A pair of locating legs 136 are pivotally mounted on each side edge of the base plate 5. Each pair of locating legs 136 are pivotally mounted within recesses in support members 138 which in turn are maintained in proper relationship with the sides of the base plate by means of locating pins 140 (FIGURE 7). Each support member 138 is secured to the sides of the base plate by means of recessed screws 142 (FIGURE 3). A pair of generally rectangular recesses 144 are provided in the lower edge portion of each support member 138 and each recess contains one of the L-shaped locating legs 136. The outer edge of each leg 136 is provided with a lug 146 (FIGURE 5) having an arcuate outer surface and a central bore therethrough aligned with a longitudinal bore inthe support member 138. The aligned bores contain a pivot pin 148 for pivotally mounting One end of each pivot pin 148 terminates in a circular bore 150 in a support member. The heads of the screws 142 (FIGURE 3) are recessed below the pivot pins 148 and threaded plugs 152 coaxial with the screws 142 and threaded into the outer portions of the support members so as to releasably engage the outer ends of the pivot pins and lock them in position. As shown in FIG. 5, each edge of the base plate 5 and cushion plate 132 is provided with a recess 154 for.

receiving the inner end portions of each leg 136. Thus, as shown in dotted lines, the inner end of each leg 136 may be pivoted completely within the recesses 144 and 154 or the legs may be pivoted outwardly so that the inner ends thereof extend below the plates 5 and 132. The top of recess 144 is provided with a stop surface 156 which contacts the outer edge of leg 136 so as to limit outward pivotal movement thereof.

,In operation, the push button 122 is depressed so as to energize the magnet or solenoid 102 so as to actuate valve member 96 to the left as viewed in FIG. 2. Air

5. onthe upper surface thereof by means of the cushion plate 132 and so that twosides of the guide boss 7 contact two sides of the rectangular opening 12 whereby one of the rectangular openings 83 in the boss 7 receives one of the arcuate corners of the opening 12. As illustrated in FIG. 1, the corner square is illustrated as in FIG. 8 with the chisel support 54 omitted. The corner square 14 is illustrated as properly mounted on the upper surface of the panel 10 so as to cut out or square the rounded corner 18 in the opening 12. The eight locating legs 136 have been indicated separately by the letters A, B, C, D, E, F, G, and H. As illustrated in FIG. 1, the right and bottom edges of the boss 7 are parallel to and contact the sides 17 and 19 of opening 12. The legs A, B, C, and D, are retracted into their respective recesses 144 and 154 as illustrated in dotted lines in FIG. 5 and are supported on the upper surface of the panel. The legs E, F, G, and H, are extended downwardly by gravity as illustrated in solid lines in FIG. 5. All of the legs have outer side surfaces which are parallel with and coplanar with one of the side surfaces of the boss 7. Thus, the bottom surface of the leg E is coplanarwith the bottom surface of the boss 7 and the right side surface of leg H is coplanar with the right side surface of the'boss 7 as illustrated in FIG. 1. Since the legs E, F, G, and H are maintained in a downward or extended position by gravity, the bottom side surface of the leg E and the right side surface of the leg H contacts the side 19 and side 17 of the opening 12 respectively. Thus, it is apparent that the bottom surfaces of the leg E and boss 7 and the right side surfaces of the leg H and the boss 7 by contacting the sides 19 and 17 respectively of the opening 12 properly align the corner square 14 in the opening 12 for cutting out the rounded corner 18. To cut out the rounded corner 18 in the panel 10, the push button 120 is depressed so as to urge the valve member 96 to the left as viewed in FIG. 2, thereby admitting air pressure via conduit 104, groove 118, and conduit 110 to the bottom of cylinder 24 and venting the top of the cylinder via conduits 112 and vent 116 so that the air pressure in the cylinder urges the piston 32 and the chisel support 54 upwardly. As the chisel support moves upwardly, the chisel 72 on the lower right hand corner as viewed in FIG. 1 cuts out the rounded corner 18 in the panel 10. Since the rounded corner 18 has its upper surface supported against one of the dies 84, and since the lower right hand chisel fits snugly within the die, the cutting edges 76 and 78 of the chisel cleanly cut out the corner without splintering the edges thereof and so that the lines of cut are in alignment with the original edges 19 and 17 of the opening 12.

After the corner 18 has been squared, the corner square 14 may then be slid either to the corner 16 or 20 for squaring these corners. Assuming the tool as slid to the left as viewed in FIG. 1 for removing the corner 20, after the tool has been moved a smalldistance parallel to the edge 19, the legs A and B drop by gravity within the opening 12 and as the tool passes over the edge 21,

the legs E and F are cammed by the edge 21 into the retracted position and supported on the upper surface of panel 10. The legs C and D remain in retracted position. As viewed in FIG. 1, when the tool 14 is properly located in relation to the corner 20 for squaring same, the left side of the leg G is in contact with the edge 21 and the lower side of the leg B is in contact with the edge 19 whereby the legs G and B and the left and lower sides of the boss 7 properly align the tool over the corner 20 so that the corner may be cut out by the lower left chisel 72. Of course, before the tool may be moved from corner 13 to corner 20, the push button 120 should be pressed so as to again extend the chisel support 54 below the panel 10. After the tool is properly located in the corner 20, the push button 120 is then depressed so as to admit compressed air into the bottom of cylinder 24 for elevating the chisels and cutting out the corner 20 with the lower left hand chisel as viewed in FIG. 1. The corners 14 and 20 may then be cut out in a similar manner merely by sliding the tool 14 along the edges 21 and 15 of opening 12 and operating the push button in a manner similar to that described above. 7

Normally, the four corners of a rectangular opening 1 in a panel may be cut .out by the tool 14 in from 10 to 15 seconds. This is many times faster than methods previously used for removing these corners. It i to be noted that the squaring of the corners is expedited since it is not necessary to rotate the tool 14 at all during use, s nce the locating legs 132 are automatically retracted and extended, and since the locating legs and boss 7 always maintain the cutting tool in proper alignment with the edges of the rectangular opening whose corners are to be squared.

Four chisels or cut-ting bits are designed into the device so that the operator will not have to rotate it for each respective corner, such as he would have to do if there were only one cutting bit provided. Having to rotate the device would create an awkward situation and would be time consuming for the operator.

Inasmuch as various changes may be made in the form, location and relative arrangement of the several parts without departing from the essential characteristics of the invention, it wili be understood that the invention is not to be limited except by the scope of the appended claims.

Iolaim:

1. A tool for cutting out irregular shaped corners of an opening in a frame to square said corners comprising a base for engagement with corner portions of the frame so that the weight of the tool is supported on the frame, power means carried by 'said base, movable cutting means below the base and carried thereby, said cutting means comprising a support connected to said power means and four rigid chisel cutting elements fixed to said support and arranged in a rectangular pattern so that the tool may cut a plurality of said corners without rotating the tool relative to said frame, at least one end portion of each chisel comprising a pair of plates extending at right angles to each other and relative to said base, the end of each plate adjacent the base being formed with a knife-like sharp cutting edge, connecting means opera tively connecting the power means to the cutting means, and control means connected to the power means for causing the power means to move the cutting means upwardly towards the base so as to cut out one of said corners.

2. A tool as defined in claim 1, wherein four dies are secured to the base adjacent saidsu-pport, each die having a recess defined by a pair of surfaces parallel to and in alignment with .the outer surfaces of a pair of said plates comprising one of said chisels.

3. A tool as defined in claim 1, wherein said connecting means includes a rod connected to said support at one end and having a portion slidab'ly mounted in an aperture through said base.

4. A tool as defined in claim 3, wherein said power means includes a cylinder mounted on the other side of said base, a piston slidable in said cylinder, the other end of said nod connected to said piston, and a pair of conduits for supplying fluid pressure connected to opposite ends of the cylinder.

5. A tool as defined in claim 4, including a pair of handles spaced on opposite sides of said cylinder and connected to said base, said control means including a valve connected to said pair of conduits and a source of air pres ure, manually operated means .on said handles connected to said valve whereby said valve may be selectively operated to apply air pressure to either of said conduits.

6. A tool as defined in claim 5, wherein said valve includes solenoid operating means and said manually operated means comprise switches.

7. A :tool as defined in claim 1 including eight locating legs each pivotally mounted on said base, said opening (having four sides defining a rectangle each side of said rectangle lbeing parallel with the outer surface of two of said legs, each leg being selectively pivotable above or below an upper flat surface of said frame.

8. A'tool as defined in claim 7 including stop means engageable with each leg when it is pivoted below said flat surface and stopping said leg in a position Where it is inclined toward said support.

9. A corner cutting device comprising a base plate, a square ledge plate secured to the under surface of the base plate, four corner chisels, means mounting the corner chisels for reciprocating movement on the base plate towards and away from the ledge plate with each corner chisel underlyinga corner of the ledge plate and with its cutting edge aligned with the outer edge of the said 7 corner, power actuated means under manual control mounted on the upper surface of the base plate and operatively connected to reciprocate the said chisels, a handle means for moving the base plate secured thereto, and means for releasably securing the device in corner mit the outer inside leg on each inside edge of the base plate when the device is located in corner cutting position to dependingly engage an inner surface of a frame to be cut so as to secure the device against lateral movement during the cutting operation of the frame.

References Cited by thev Examiner UNITED STATES PATENTS 655,421 8/00 Tyler 144217 1,620,374 3/27 Maloney W 14368 1,898,956 2/33 Ha-rvie 143-68 2,612,951

10/52 Palrnleaf 83639 X LESTER M. SWINGLE, Primary Examiner. WILLIAM W. DYER, JR., Examiner. 

1. A TOOL FOR CUTTING OUT IRREGULAR SHAPED CORNERS OF AN OPENING IN A FRAME TO SQUARE SAID CORNERS COMPRISING A BASE FOR ENGAGEMENT WITH CORNER PORTIONS OF THE FRAME SO THAT THE WEIGHT OF THE TOOL IS SUPPORTED ON THE FRAME, POWER MEANS CARRIED BY SAID BASE, MOVABLE CUTTING MEANS BELOW THE BASE AND CARRIER THEREBY, SAID CUTTING MEANS COMPRISING A SUPPORT CONNECTED TO SAID POWER MEANS AND FOUR RIGID CHISEL CUTTING ELEMENTS FIXED TO SAID SUPPORT AND ARRANGED IN A RECTANGULAR PATTERN SO THAT THE TOOL MAY CUT A PLURALITY OF SAID CORNERS WITHOUT ROTATING THE TOOL RELATIVE TO SAID FRAME, AT LEAST ONE END PORTION OF EACH CHISEL TO SAID FRAME, AT LEAST ONE END PORTION OF ANGLES TO EACH OTHER AND RELATIVE TO SAID BASE, THE END OF EACH PLATE ADJACENT THE BASE BEING FORMED WITH A KNIFE-LIKE SHARP CUTTING EDGE, CONNECTING MEANS OPERATIVELY CONNECTING THE POWER MEANS TO THE CUTTING MEANS, AND CONTROL MEANS CONNECTED TO THE POWER MEANS FOR CAUSING THE POWER MEANS TO MVOE THE CUTTING MEANS UPWARDLY TOWARDS THE BASE SO AS TO CUT ONE OF SAID CORNERS. 